Generally, a BFT is constituted of a bus bar formed by press working a metal flat plate and a resin-made housing so insert molded as to cover other portions of the bus bar than the exposed portion thereof. The bus bar includes integrally therewith an input side terminal part connectable with the positive pole of a battery, an output side terminal part connectable by a load side wire, a welding part for connecting together the input and output side terminal parts, and a tuning fork terminal (standing terminal) connectable by an external part such as an external fuse (see the patent document 1).
FIGS. 8 and 9 explain an example of a conventional BFT: FIG. 8 is a perspective view of a bus bar constituting the BFT; and, FIG. 9 is a perspective view of the BFT. This type of BFT is generally manufactured in the following order.
Firstly, a metal flat plate is press molded to form a bus bar 210 shown in FIG. 8. The bus bar 210 includes: an input side terminal part 211 and output side terminal parts 212, 213, respectively constituting the main plate part; welding parts 218, 219 for connecting together the input and output side terminal parts 211 and 212, 213; an external connection terminal 225; and, tuning fork terminals 221, 222 serving as standing terminals. The tuning fork terminals 221, 222 are used to connect external fuses. Here, the external connection terminal 225 is connected to the output side terminal parts 212, 213 by bridge portions 227, 228 to be cut later in cut expected portions shown by reference sign K. Also, one tuning fork 221 is connected to the input side terminal part 211 by a base part 223 formed continuously with the base end of the tuning fork terminal 221, whereas the other tuning fork terminal 222 is connected to the external connection terminal 225 by a base part 224 formed continuously with the base end of the tuning fork terminal 222.
Next, the base ends of the tuning fork terminals 221, 222 are bent 90° to erect the terminals 221, 222 to be orthogonal to the input side terminal 211 and output side terminals 212, 213 serving as the main plate part. Then, low meting metal, namely, tin chips 216, 217 are caulked and welded to the caulking pieces 214, 215 of the welding parts 218, 219 to complete the welding parts 218, 219. Next, the bus bar 210 is set in a molding mold and, as shown in FIG. 9, a resin-made housing 250 is insert molded. After insert molding, the bridge portions 227, 228 shown in FIG. 8 are cut in the cutting portions K, thereby producing a BFT 201 in which the bus bar 210 and housing 250 are integrated with each other.
In this BFT 201, the input and output side terminal parts 211 and 212, 213 are exposed from the housing 250, thereby enabling connection thereof to a battery terminal or a load side wire. Also, the tuning fork terminals 221, 222 are exposed into an external part mounting part 258 surrounded by a protection wall, the welding part 218, 219 are exposed into window portions 256, 257, and the external connection terminal 225 is exposed into a connector part 259.